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Novel cellulose-derived hybrid carbon nanofibre (CNF)/carbon nanotubes (CNTs) electrode-based structural supercapacitors, combined with a solid electrolyte, have been produced. Galvanostatic charge/discharge and electrochemical impedance spectroscopy measurements were used to assess the electrodes’ performance. The CNF/CNTs electrodes have a better capacitive performance than the plain CNF electrodes; 0.91 ± 0.02 and 3.35 ± 0.05 mF cm−2 for CNF and CNF/CNTs, respectively. A Raman spectroscopic approach was used to investigate the stress transfer properties of the CNF within a poly(methyl methacrylate) (PMMA) resin matrix. Deformation of the carbon structures was observed via shifts towards a lower wavenumber position of the G band (~ 1590 cm−1) for CNF and CNF/CNTs samples processed at a carbonization temperature of 2000 °C. Moduli of these fibres were estimated to be ~ 145 and ~ 271 GPa, respectively, suggesting the growth of CNTs not only enhances the capacitive performance but also the mechanical performance of the structural supercapacitors. [ABSTRACT FROM AUTHOR]

ABSTRACT Three-dimensional polymer nanofibrous mats with tunable wettability have been fabricated using a single step non-conductive template assisted electrospinning process. Cellulose acetate nanofibers are electrospun over a nylon mesh, which acts as the template. The as-deposited fiber mat is removed from this template to produce a free standing three-dimensional micropatterned nanofibrous mat. By simply varying the template mesh dimensions, the fraction of the air-liquid interface can be changed which allows control of the wetting mechanics. It is shown that the water contact angle can be varied from about 30° for a planar network to about 140° for a patterned mat implying a complete transition from hydrophilic to hydrophobic behavior. Furthermore, upon stretching the fiber mat loses its pattern irreversibly and reducing the contact angle from 140° to 110° with increasing stretching. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44709. [ABSTRACT FROM AUTHOR]

• An electrospun oil sorbent, derived from cigarette filters, was produced. • The sorbent exhibited an oil sorption capacity of 93.7 g/g. • The result is higher than that of all previous cigarette filter derived sorbents. A highly effective oil sorbent, made from cigarette filters, was produced using a low complexity, single-step process. This was done to address the dual issues of oil pollution and cigarette filter litter. The oil sorption capacity was found for electrospun cellulose acetate sorbents, made from both virgin cellulose acetate and cigarette filters. Not only did the cigarette filter derived sorbent have a higher oil sorption capacity than sorbents found in other studies (with a capacity of 93.7 g/g), but the sorbent was also produced using a less complex and less energy-intensive method. Additionally, the oil sorption capacity for the cigarette filter sorbent was found to be higher than that of a virgin cellulose acetate sorbent. This was thought to be due to the additive, glycerol triacetate (GA), found within the cigarette filters. This means that not only does sourcing the cellulose acetate from cigarette filters tackle cigarette filter pollution, but it also produces a more effective sorbent. Therefore, the cigarette filter derived oil sorbent produced in this study has the potential to be a highly effective, and more sustainable, solution for the remediation of oil pollution. [ABSTRACT FROM AUTHOR]

The development of co-electrospun (co-ES) hollow microfibrous assemblies of an appreciable thickness is critical for many practical applications, including filtration membranes and tissue-mimicking scaffolds. In this study, thick uniaxially aligned hollow microfibrous assemblies forming fiber bundles and strips were prepared by co-ES of polycaprolactone (PCL) and polyethylene oxide (PEO) as shell and core materials, respectively. Hollow microfiber bundles were deposited on a fixed rotating disc, which resulted in non-controllable cross-sectional shapes on a macroscopic scale. In comparison, fiber strips were produced with tuneable thickness and width by additionally employing an x – y translation stage in co-ES. Scanning electron microscopy (SEM) images of cross-sections of fiber assemblies were analyzed to investigate the effects of production time (from 0.5 h to 12 h), core flow rate (from 0.8 mL/h to 2.0 mL/h) and/or translation speed (from 0.2 mm/s to 5 mm/s) on the pores and porosity. We observed significant changes in pore size and shape with core flow rate but the influence of production time varied; five strips produced under the same conditions had reasonably good size and porosity reproducibility; pore sizes didn't vary significantly from strip bottom to surface, although the porosity gradually decreased and then returned to the initial level. [ABSTRACT FROM AUTHOR]

Abstract: In this work, the effects of process parameters on the deposition of single component and compound core–shell jets in near-field electrospinning are reported. It is shown that the working distance and fibre collector speed have a more significant influence on the deposition of a single jet than the flow rate. In the case of a compound jet, it is shown that jet deposition onto aluminium foil results in a linear fibre form, but on glass slides it appears as a random fibre network. The fabrication of aligned and patterned core–shell structured fibres is demonstrated by coaxial electrospinning of sugar and polycaprolactone (PCL) solutions. Aligned sugar-PCL core–shell fibres with diameters of ∼1.2 μm are deposited on an x–y translation stage, 10 cm below the coaxial spinneret. Complex patterns of sugar-PCL core–shell fibres with average diameters ranging from 72 to 175 μm are fabricated by reducing the working distance to 2 cm. [Copyright &y& Elsevier]

• Porous superhydrophobic nanofibers were prepared using electrospinning. • A highly volatile solvent combined with electrospinning in humid conditions yielded pores on the surface of the fibers. • The porous fibers were superhydrophobic with a water contact angle of 165° and an oil contact angle of ∼0°. • The prepared fibers exhibited an oil sorption capacity of 60 g/g. Porous superhydrophobic nanofibrous networks based on cellulose acetate butyrate (CAB) were prepared using electrospinning. The morphology and wettability of the prepared fibrous networks was studied using scanning electron microscopy and static contact angle measurements. The porous nanofiber networks exhibited superhydrophobicity and superoleophilicity with a water contact angle of ∼165° and an oil contact angle of ∼0°. The porous nature of the nanofibres themselves is thought to lead to an increased surface area making them suitable for sorption applications. Due to their hydrophobic and oleophilic nature, they were tested for their oil sorption capacity. They demonstrated an oil sorption capacity of ∼60 g/g for motor oil, which is four times that of commercially used polypropylene. The nanofibrous mats also demonstrated excellent reusability, retaining ∼80% of their sorption capacity for up to 5 cycles of use. [ABSTRACT FROM AUTHOR]

Sustained release and prevention of burst release for low half-life drugs like Diclofenac sodium is crucial to prevent drug related toxicity. Electrospun nanofibers have emerged recently as potential carrier materials for controlled and sustained drug release. Here, we present a facile method to prevent burst release by tuning the surface wettability through template assisted micropatterning of drug loaded electrospun cellulose acetate (CA) nanofibers. A known amount of drug (Diclofenac sodium) was first mixed with CA and then electrospun in the form of a nanofabric. This as-spun network was hydrophilic in nature. However, when electrospinning was carried out through non-conducting templates, viz nylon meshes with 50 and 100 μm size openings, two kinds of hydrophobic micro-patterned CA nanofabrics were produced. In vitro transdermal testing of our nanofibrous mats was carried out; these tests were able to show that it would be possible to create a patch for transdermal drug release. Further, our results show that with optimized micro-patterned dimensions, a zero order sustained drug release of up to 12 h may be achieved for the transdermal system when compared to non-patterned samples. This patterning caused a change in the surface wettability, to a hydrophobic surface, resulting in a controlled diffusion of the hydrophilic drug. Patterning assisted in controlling the initial burst release, which is a significant finding especially for low half-life drugs. [ABSTRACT FROM AUTHOR]

Cellulose nanofibres have been fabricated by electrospinning of a cellulose acetate solution followed by deacetylation. The cellulose nanofibres were then carbonized using temperatures in the range 800–2200°C and the resulting carbon nanofibres (CNFs) were characterized using transmission electron microscopy, X-ray diffraction and Raman spectroscopy. A graphitic structure was observed for CNFs treated at a relatively low temperature of 1500°C, with no obvious skin-core heterogeneity observed for fibres treated up to 2200°C, suggesting a possible advantage of using nano-scale precursors. The effective Young’s modulus of the CNFs was assessed using an in situ Raman spectroscopic technique following the shift in the position of the G′ (2D) band located at ∼2660cm−1 and relating this to a calibration established for a range of other carbon fibres. Using this approach the moduli of the CNFs were found to be ∼60 and ∼100GPa for samples carbonized at 1500 and 2200°C, respectively. [ABSTRACT FROM AUTHOR]

The effect of electrospun cellulose nanocrystals (CNCs)-polyetherimide (PEI) hybrid nanofibrous mats on Mode I and Mode II interlaminar fracture toughness of unidirectional carbon/epoxy composite laminates is demonstrated. It is shown that the CNCs reinforced PEI nanofibrillar interleaves result in a ~28% increase in Mode I initial fracture toughness values compared to neat PEI nanofibrous interleaves. Specifically, the interrelated micro- and nano-scale toughening mechanisms including carbon fibre bridging, fibre necking, fibre rupture with CNCs aggregates, and nanofibre rupture contributed to the fracture toughness improvements under Mode-I loading. Nano-scale mechanisms of shear hackles, and crack pinning by CNCs aggregates increased the Mode II fracture toughness up to ~3 kJ/m2 as a result of a 6 wt% CNCs reinforced PEI nanofibrillar mat interleave. Interleaving laminated composites with electrospun CNCs-PEI hybrid nanofibrillar mats has been demonstrated as a novel and prospective strategy to strengthen and toughen interlaminar zones of carbon/epoxy composite laminates. [ABSTRACT FROM AUTHOR]